Solid line = floor (spellings that unambiguously belong to the group). Shaded band up to the dashed edge = ceiling (the most it could reach if every ambiguous spelling counted here).
Meredith was more common in the past and has since settled at a lower, steady level. All-time it's been given to 84,728 U.S. babies, the 943rd most common name by sound today, peaking at 2,180 in 1980, with 656 in 2025.
By sound, Meredith also includes the spellings Meridith.